Need help with my GTO


New member
I own a 66 Pontiac GTO with an original 389 engine that I'm in the process of restoring. A freeze plug has rusted thru on the passenger side head on the rear.. by the firewall. The freeze plug opening is 1-3/8". I bought a Dorman rubber expansion plug, P/N 570-007, but I think that the heat from the head might melt the rubber. I was looking at the Dorman copper expansion plugs, but the smallest size close to what I need is 1-1/2 P/N 568-009. I was wondering if anyone has an easy fix for this problem, as I am trying to keep from doing major engine work, removing the head, and/or motor, as there isn't much room between the head and firewall.
The motor was rebuilt (and runs) 10 years ago by a local speed shop that has gone out of business. Any help and /or ideas would be greatly appreciated.
Thanks, Kenny Martin.